The present invention relates to a hammering or roto-hammering tool assembly known under the name of a jack-hammer, a concrete-breaker, or a drill hammer. It is known that such an apparatus has handles serving to hold and guide the tool. The power supply of the tool assembly can be of any convenient form.
Since such a tool assembly experiences extreme vibrations, an attempt has been made to make the tool easier to control by suspending the handles with respect to the body of the apparatus. For this purpose, one solution consists in mounting the handles on a hollow cylindrical head which constitutes a jack sliding on the body of the hammer.
The disadvantages of this known solution are many.
In particular, the effectiveness of a suspension decreases when friction occurs. There are enormous frictional forces on a large diameter during the movement of the sliding head which carries the handles. This movement likewise occurs over a great length. Consequently, it has been found that this movement gives rise to the appearance of hard points after a certain period of use at the work places.
In the case of a compressed air powered tool, the air comes into the handles, which are suspended, and is then fed to the body of the tool, which is not suspended. Sealing joints or flexible delivery tubing should, therefore, be provided between the two parts, suspended and not suspended.
If the pick or breaking tool of the tool assembly happens to become jammed, it is not possible to make the apparatus operate at an idling condition to loosen the pick, as is customary on nonsuspended apparatus.